公开(公告)号：US20030137400A1

公开(公告)日：2003-07-24

申请号：US10056398

申请日：2002-01-23

Applicant: Intermec IP Corp.

Inventor： Harley Kent Heinrich ,  Vijay Pillai ,  David E. Dieska

IPC: H04Q001/30

CPC classification number: G06K19/0701 ,  G06K19/0723 ,  G06K19/073

Abstract: The present invention provides an RFID transponder that includes a state holding cell that maintains the present state of the RFID transponder during temporary losses of power. After power is restored to the RFID transponder, the state holding cell restores the present state to the RFID transponder so that transactions with an RFID interrogator can continue without having re-transmit redundant commands. The RFID transponder further comprises an RF front end adapted to receive an interrogating RF signal. An analog circuit is coupled to the RF front end and is adapted to recover analog signals from the received interrogating RF signal. The analog circuit provides state information defining a desired state of the RFID transponder corresponding to the analog signals. A digital state machine is coupled to the analog circuit and adapted to execute at least one command in accordance with the state information. A memory is coupled to the digital state machine and is adapted to store and retrieve digital data responsive to the at least one command executed by the digital state machine. A power capacitor is coupled to the RF front end and derives a voltage rectified from the interrogating RF signal to charge the power capacitor. The power capacitor thereby provides electrical power for the analog circuit, the digital state machine and the memory. The state holding cell is coupled to the analog circuit and the digital state machine and is adapted to maintain the state information during a loss in power provided by the power capacitor due to lapse in receipt of the interrogating RF signal by the RF front end.

Abstract translation: 本发明提供一种RFID应答器，其包括状态保持单元，其在暂时的功率损耗期间保持RFID应答器的当前状态。 在将电力恢复到RFID应答器之后，状态保持单元将当前状态恢复到RFID应答器，使得与RFID询问器的交易可以在不重新传输冗余命令的情况下继续进行。 RFID应答器还包括适于接收询问RF信号的RF前端。 模拟电路耦合到RF前端，并且适于从接收的询问RF信号中恢复模拟信号。 模拟电路提供定义对应于模拟信号的RFID应答器的期望状态的状态信息。 数字状态机耦合到模拟电路并且适于根据状态信息执行至少一个命令。 存储器耦合到数字状态机，并且适于响应于由数字状态机执行的至少一个命令来存储和检索数字数据。 功率电容器耦合到RF前端，并导出从询问RF信号整流的电压，以对功率电容器充电。 因此，电力电容器为模拟电路，数字状态机和存储器提供电力。 状态保持单元耦合到模拟电路和数字状态机，并且适于在由RF前端接收到询问RF信号的过程中由功率电容器提供的功率损耗期间维持状态信息。